Colin Maudry
927f56cb1c
Implémente la fonction select_retained() pour la rétention multi-paliers: - Paliers fixes: horaire/12h, 12h/72h, quotidien/21j - Palier mensuel: 12 mois calendaires - Fonction pure, pas de dépendances sur d'autres modules backup Fixes #89 Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
50 lines
1.5 KiB
Python
50 lines
1.5 KiB
Python
from collections.abc import Iterable
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from datetime import datetime, timedelta
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# (période, horizon) pour les paliers à période fixe
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_FIXED_TIERS = (
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(timedelta(hours=1), timedelta(hours=12)), # horaire / 12 h
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(timedelta(hours=12), timedelta(hours=72)), # 12 h / 72 h
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(timedelta(days=1), timedelta(days=21)), # quotidien / 21 j
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)
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_MONTHLY_HORIZON = 12 # mois calendaires
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def _select_fixed(timestamps, now, period, horizon):
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cutoff = now - horizon
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buckets: dict[int, datetime] = {}
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for t in timestamps:
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if t > now or t < cutoff:
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continue
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idx = int((now - t) // period)
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if idx not in buckets or t > buckets[idx]:
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buckets[idx] = t
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return set(buckets.values())
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def _month_index(d: datetime) -> int:
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return d.year * 12 + (d.month - 1)
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def _select_monthly(timestamps, now):
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now_idx = _month_index(now)
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buckets: dict[int, datetime] = {}
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for t in timestamps:
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if t > now:
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continue
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idx = _month_index(t)
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if idx > now_idx or now_idx - idx >= _MONTHLY_HORIZON:
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continue
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if idx not in buckets or t > buckets[idx]:
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buckets[idx] = t
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return set(buckets.values())
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def select_retained(timestamps: Iterable[datetime], now: datetime) -> set[datetime]:
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items = list(timestamps)
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retained: set[datetime] = set()
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for period, horizon in _FIXED_TIERS:
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retained |= _select_fixed(items, now, period, horizon)
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retained |= _select_monthly(items, now)
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return retained
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